1. Field of the Invention
The invention relates to microwave heating and means for preparing circular elongated objects.
2. Description of the Prior Art
Microwave heating is becoming increasingly popular, particularly, in the preparation of foodstuffs. The energy is radiated within an enclosure from an energy source, such as a magnetron. The waves are radiated and reflected within the enclosure to result in high frequency oscillatory movement of the molecules in the load to cause heating by molecular friction. The materials being heated have differing dielectric constant values which results in uneven heating due to varying absorption of the microwave energy. The surface coloration, therefore, is difficult to control, particularly, in the preparation of such foodstuffs as frankfurts.
An example of a prior art teaching is U.S. Pat No. 3,591,751 issued July 6, 1971 to C. E. Goltsos which discloses a plurality of half-wavelength rods to provide rapid heating of the rods by the microwave energy. The absorbed heat is then transferred by conduction to a supported load. This technique not only results in problems caused by the heating of the rods but is difficult to implement in the processing of objects which are not flat. Another example of a prior art teaching is found in copending application Ser. No. 554,861 filed Mar. 3, 1975 by G. MacMaster et al. and assigned to the assignee of the present invention. In this embodiment a plurality of conductive metal members are provided, each folded in such a manner as to provide a continuous apex portion and two spaced apart adjacent leg portions. The conductive members are disposed in a linear array and the apparatus is not efficient for heating circular elongated objects.
A need arises, therefore, for an improved microwave heating means for processing circular elongated objects such as frankfurts.